Stop-watch.



No. 826,444. PATENTED JULY 17, 1906.

J. PBTRILLO. STOP WATCH.

APPLIOATION FILED MAY 24. 1905,.

2 SHEETBSHEET 1.

I Ja a 170 ZWp'dio, 49. MQQW j 4 No. 826,444.. PATENTED JULY 17, 1906. Y J. PETRILLO.

STOP WATCH.

APPLIOATION FILED MAY24,1906.

2 SHEETS-SHEET 2.

UNITED STATES PA TENT OFFICE.

STOP-WATCH.

Specification of Letters Patent.

Patented July 17, 1906.

Application filed May 24,1905. Serial No. 261,925.

To all whom it may concern.-

Be it known that I, JOSEPH PETRILLo, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Stop-Watches, of which the following description, in connection with the accompanying drawings, is a specification, like numerals on the drawings representing like parts.

This invention relates to stop-watches, and

particularly to the mechanism for resetting the indicating-hand to zero after it has been in operation to indicate an interval of time.

Most stop-watches are made with an arbor carrying an indicating-hand, usually a seconds-hand, and suitable means are provided for throwing said arbor into gear with the train of gearing operating the main hands of the watch whenever it is desired to indicate an interval .of time by said indicating-hand and to disconnect said arbor from the train of gearing when it is desired to stop the indicating-hand in order to read the time. For resetting the indicating-hand to zero before making a new indication the arbor has generally been provided with a heart-cam, against which a spring-impelled arm or lever acts, and said arm or lever is thrown out of engagement with the heart-cam, while the indicating hand is operatively connected with the train of gearing, but is brought against the heart-cam when said indicatinghand is disconnected from the train of gearing, said spring-impelled arm by engaging the cam operating to reset the indicatinghand to zero.

The present invention has for its object to provide a more satisfactory way of resetting the indicating-hand to zero by providing means which act in a ositive manner and prevent any vibration of the indicating-hand after it has been brought to Zero position.

The particular features wherein my invention resides will be more fully hereinafter described and then pointed out in the claims.

In the drawings, Figure 1 is an enlarged view of a watch having my improvements applied thereto. Figs. 2 and 3 are detail views showing the parts in different positions.

3 designates the arbor on which the indicating-hand is mounted, said arbor being supported in suitable bearings and preferablybeing driven so that the hand thereon (not shown) will indicate seconds. Fast to the arbor 3 is a gear 4, which may be either a toothed gearor a friction-gear. Said gear is adapted to mesh with a pinion 5, carried by a swinging arm 6, suitably pivoted, as at 7. The pinion 5 is mounted on an arbor 8, journaled in the arm 6, and said arbor 8 carries another pinion 9, which is adapted to continually mesh with a gear 10, forming part of the regular train of gearing, by which the main hands of the watch are driven. The arm 6 is acted upon by a suitable spring 11, which tends normally to throw the pinion 5 into mesh with the gear 4, and said arm is controlled as to its position by means of an operating-cam 12, which acts against a nose 13, rigid with the arm 6. The cam 12 rotates about a stud or pin-14 and isprovided with notches 15 and intermediate elevated portion 16. Rigid with the cam is a ratchet wheel 17, (shown in dotted lines, Fig. 1,) with which a pawl 18 cooperates, said pawl being mounted upon a resilient arm 19, which is fixed at one end to the frame of the watch, as at 200. The arm 19 has projecting therefrom a pin or stud 201, which stands under the shank 210 of the movable stem 220 of the watch, so that by depressing said stem the left-hand end of the arm 19 is forced downwardly thereby to advance the ratchet 17 and cam 12. So long as the gears 4 and 5 are out of engagement with each other the arbor 3 remains at rest. When it is desired to start the indicating-hand, the stem 210 is depressed thereby to turn the cam 12 sufficiently to bring a notch 15 thereof under the nose 13, as shown in Fig. 2. When this occurs, the spring 11 acts to throw the arm 6 toward the gear 4, thereby bringing the pinion 5 into mesh therewith, it being understood that this slight movement of the arbor 8 doesnot throw the gear 9 out of engage= ment with the driving-gear 10. As soon as the gears 4 and 5 are in mesh with each other the arbor 3 is connected through said gears with the train of gearing driving the main hands, and thereby said arbor will rotate, and preferably the gearing is such that said indicating-hand will indicate seconds. When it is desired to stop the movement of the indicating-hand, the stem 210 is given another impulse, thereby advancing the cam 12 into the position shown in Fig. 3, in which position one of the elevated parts 16 of the cam is brought under the nose 13 and the arm 6 is swung away from the gear 4, thereby to disconnect the pinion 5 therefrom. These parts with the exception of the particular form of resilient arm 19 are such as are found in many stop-watches and form no part of my present invention, which relates. more particularly to the means for resetting the indicating-hand to Zero.

As herein shown, the gear 4 has projecting therefrom a pin or pro ection 20, which is adapted to be engaged by one or the other of two setting-fingers 21 and by said fingers brought to the Zero position. These settingfingers are pivotally mounted upon a swinging lever or member 23 and each has pivoted thereto at its central portion a link 24:, said links 24 being both pivoted, as at 25, to a fixed point. The member 23 is suitably pivoted to the frame of the watch, as at 26, and it carries a nose or projection 27, adapted to cooperate with the cam 12. Said member is acted upon by a suitable spring 28, which tends normally to throw it toward the right.

The nose 27 and the cam 12 are so arranged that when the gear liS connected with the train of gearing for driving the main hands of thewatch the setting-fingers are re tracted, as shown in Fig. 2, and are held retracted by the engagement of the nose 27 with an elevated portion 16 of the cam 12, as shown in Fig. 2.

As stated above, when it is'desired to stop the rotation of the indicating-hand the frame is given a forward impulse and brought into the position shown in Fig. 3, whereby the arm 6 is swung to disengage the gears 4 and 5. The length of the elevated portion 16 of the cam 12 is such that during this entire forward movement of the cam the projection 27 is still engaged by the same elevated portion 16 of the cam, as shown in Fig. 3, so that the settingfingers 21 are still retracted. When after reading the indication it is desired to reset the indicating-hand, the cam is given a third forward impulse, which brings it into such position that the projection 27 is alined with a notch 15, whereupon the spring 28 comes into play to throw the setting-arm 23 forward into the position shown in Fig. 1. Since the settin -fingers are pivoted to the setting-arm 23, the forward movement of the latter carries the fingers bodily to the right, Figs. 2 and 3, and during this movement the ends of said fingers pass from the left-hand side of the arbor 3 to the righthand side thereof, as shown in Fig. 1, and at the same time they are opened away from each other and then closed together, owin to the link connection 24-, this opening and closing movement, combined with the forward movement, bringing the ends 30 of said fingers into engagement with the pin or projection 20 regardless of the position of the latter and turning the gear-wheel 4 into the position shown in Fig. 1, in which position theindicatinghand stands at zero.

By using two setting-fingers 21, which openand close and also move forward, the pin 20 is sure to be engaged by one or the other of the fingers, and when the fingers are brought into the position shown in Fig. 1 the projection 20 is caught between them, and therefore the arbor and its indicatin -hand is always positively brought into an held in zero position. The settin -fingers act more positively than the heart-shaped mechanism usually used and prevent any vibration of the indicating-finger when it is brought back to indicating position.

I prefer to use the resilient armor member 19 for carrying the pawl 18 rather than a pivoted spring-actuated member, because this construction involves fewer parts and isless liable to get out of order.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a stop-watch, an arbor for carrying an indicatinghand, a gear fast thereon, means to connect said gear withand disconnect it from the train of gearing driving-the main hands of the-Watch, and means to set said ar' bor to zero position, said latter means comprising a swinging setting-arm, a pairof setting-fingers carried by said arm and pivoted thereto, and a projection rigid with the gear to be engaged by said fingers.

2. In a stop-watch, an arbor for carrying an indicating-hand, a gear fast thereon, means to connect said gear with and disconnect it from the train of gearing driving the main hands of the watch, and means to set said. arbor to Zero position, said latter-meanscomprising a spring-actuated swinging arm, a pair of setting-fingers carried by said arm and pivoted thereto, means to open and close said fingers as the setting-arm swings, and a proj ection carried by the gear to be engaged by said fingers.

3. In a stop-watch, an arbor for carrying. an indicating-hand, a gear fast thereon, means to connect said gear with and disconnect it from the train of gearing driving the main hands of the watch, and means to set said arbor at zero position, said latter means-comprising a spring-actuated swinging settingarm, a pair of setting-fingers pivoted at one end to said setting-arm, a link pivoted to the central portion of each setting-finger, said links being also pivoted to a fixed point, and a projection carried by said gear to be engaged by said setting-fingers.

1. In a stop-watch, an arbor for carrying an indicating-hand, a gear fast thereon, means to connect said gear with and disconnect it from the train of gearing which drives-the main hands of the watch, and means to set said arbor at zero position, said latter means comprising a pair of setting-fingers, means to move said fingers transversely of the axisof rotation of the arbor thereby to carry the 1 In testimony whereof I have signed my ends of the fingers from one side of said axis name to this specification in the presence of to the other, means to cause the fingers to two subscribing Witnesses.

open awayfrom each other and close together JOSEPH PETRILLO. during such movement, and a projection Witnesses: rigid with the gear to be engaged by the fin- LOUIs C. SMITH,

gers. MARGARET A. DUNN. 

